Markdown being a simple format, it does not offer any way to attach additional metadata to a note. The community came up with a solution by inserting a YAML header at the top of each note to contain its metadata. This method is widely supported among Zettelkasten softwares, including zk.
---
title: Improve the structure of essays by rewriting
date: 2011-05-16 09:58:57
keywords: [writing, essay, practice]
---zk supports the following metadata:
| Key | Description |
|---|---|
title |
Title of the note – takes precedence over the first heading |
date |
Creation date – takes precedence over the file date |
tags |
List of tags attached to this note |
keywords |
Alias for tags |
aliases |
Alternative titles for this note, used by --mention |
All metadata are indexed and can be printed in zk list output, using the template variable {{metadata.<key>}}, e.g. {{metadata.description}}. The keys are normalized to lower case.